Q: A laser emits green light with a wavelength of $$515\ \mathrm{nm}. $$What is the frequency of this light? (Speed of light $$c = 3.00 \times 10^8$\ \mathrm{m/s})$$

$$5.83 \times 10$$^{14}$$\ \mathrm{Hz}$$

Q: According to the de Broglie hypothesis, what is the wavelength of an electron (mass $$9.11 \times 10$$^{-31}$$\ \mathrm{kg}) $$moving at $$2.45 \times 10^6$\ \mathrm{m/s}$$? ($$h = 6.626 \times 10$$^{-34}$$\ \mathrm{J\cdot s})$$

$$2.97 \times 10$$^{-10}$$\ \mathrm{m}$$

Question 1

Which of the following best explains why electrons in atoms cannot be directly observed without altering their behavior?

Accepted Answer

Electrons are so small that any attempt to observe them, even with light, changes their energy and position.

Question 2

A laser emits green light with a wavelength of $$515\ \mathrm{nm}. $$What is the frequency of this light? (Speed of light $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$5.83 	imes 10$$^{14}$$\ \mathrm{Hz}$$

Question 3

Which of the following statements about the electromagnetic spectrum is correct?

Accepted Answer

Gamma rays have higher energy and shorter wavelengths than visible light.

Question 4

A metal surface emits electrons when struck by yellow light. What will happen if the surface is struck with ultraviolet light?

Accepted Answer

Electrons will be ejected, and they will have greater kinetic energy than those ejected by yellow light.

Question 5

Which equation correctly relates the energy of a photon to its wavelength?

Accepted Answer

$$E = \dfrac{hc}{\lambda}$$

Question 6

According to the de Broglie hypothesis, what is the wavelength of an electron (mass $$9.11 	imes 10$$^{-31}$$\ \mathrm{kg}) $$moving at $$2.45 	imes 10^6$\ \mathrm{m/s}$$? ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s})$$

Accepted Answer

$$2.97 	imes 10$$^{-10}$$\ \mathrm{m}$$

Question 7

Which of the following best summarizes the Heisenberg uncertainty principle?

Accepted Answer

The more accurately you know the position of an electron, the less accurately you can know its velocity.

Question 8

Which quantum number determines the shape of an atomic orbital?

Accepted Answer

Angular momentum quantum number $$l$$

Question 9

How many $$d$$ orbitals are present in the $$n=3$$ principal energy level?

Accepted Answer

5

Question 10

Which transition in a hydrogen atom emits light with the shortest wavelength?

Accepted Answer

$$n=3 to$$ $$n=2$$

Question 11

A 100-watt light bulb emits light at a wavelength of $$525\ \mathrm{nm}. $$How many photons are emitted per second? ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s}$$, $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$2.64 	imes 10$$^{20}$$

Question 12

Which of the following is a correct statement about atomic emission spectra?

Accepted Answer

Each element has a unique line spectrum because its electrons transition between specific energy levels.

Question 13

Which quantum numbers are needed to uniquely describe a single electron in an atom?

Accepted Answer

Principal quantum number $$n$$, angular momentum quantum number $$l$$, magnetic quantum number $$m_l$$, and spin quantum number $$m_s$$

Question 14

Which of the following best explains why we do not observe wave properties for a baseball thrown at a ballpark?

Accepted Answer

Because of the baseball's large mass, its de Broglie wavelength is minuscule and insignificant compared to its size.

Question 15

Which of the following is true about the relationship between wavelength and frequency for electromagnetic waves?

Accepted Answer

Wavelength and frequency are inversely proportional.

Question 16

A photon has an energy of $$3.75 	imes 10$$^{-19}$$\ \mathrm{J}. $$What is its wavelength? ($$h = 6.626 	imes 10$$^{-34}$$\ \mathrm{J\cdot s}$$, $$c = 3.00 	imes 10^8$\ \mathrm{m/s})$$

Accepted Answer

$$530\ \mathrm{nm}$$

Question 17

Which quantum number determines the number of subshells in a principal energy level?

Accepted Answer

Principal quantum number $$n$$

Question 18

Which of the following best describes the difference between a bright green laser and a dim green laser?

Accepted Answer

The two lasers emit light of the same frequency, but the bright green laser has a greater amplitude.

Question 19

Which of the following is a property of $$s$$ orbitals?

Accepted Answer

They are spherical in shape and have $$n-1$$ nodes.

Quantum-Mechanical Model of the Atom: Structure, Properties, and Light

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